Method and device for measuring tread depth of a tire

Abstract

A method of measuring a tread depth of a tire includes transmitting at least one radio wave from a transmitter through a tread of the tire. The at least one radio wave reflected from a road surface is received with a receiver. The tread depth of the tire is determined based on comparing the at least one radio wave reflected from the road surface with the at least one radio wave from the transmitter.

What is claimed is: 
     
       1. A method of measuring a tread depth of a tire, the method comprising:
 transmitting at least one radio wave from a transmitter through a tread of the tire; 
 receiving the at least one radio wave reflected from a road surface with a receiver; 
 determining the tread depth of the tire based on comparing the at least one radio wave reflected from the road surface with the at least one radio wave from the transmitter; and 
 generating a distance data set based on a plurality of radio waves; 
 wherein the determining of the tread depth of the tire is based on at least one of measuring an elapsed time between when the at least one radio wave was transmitted by the transmitter and when the at least one radio wave reflected from the road surface was received by the receiver or measuring a phase of the at least one radio wave that was transmitted by the transmitter and a phase of the at least one radio wave reflected from the road surface and received by the receiver, 
 wherein the at least one radio wave includes the plurality of radio waves, 
 wherein the distance data set includes distances obtained during a predetermined degree of rotation of the tire, and 
 wherein determining the tread depth of the tire includes selecting a smallest distance value from the distance data set. 
 
     
     
       2. The method of  claim 1 , wherein the predetermined degree of rotation of the tire is determined by an accelerometer. 
     
     
       3. The method of  claim 1 , wherein the predetermined degree of rotation of the tire is between negative 45 degrees and positive 45 degrees relative a vertical line from the road surface through a center of the tire. 
     
     
       4. The method of  claim 1 , including generating a plurality of distance data sets each corresponding to a single rotation of the tire and averaging a smallest distance value for each of the plurality of distance data sets to obtain the tread depth of the tire. 
     
     
       5. The method of  claim 1 , wherein the transmitter is located on a first chipset and the receiver is located on a second chipset and the transmitter and the receiver are each in electrical communication with at least one antenna. 
     
     
       6. The method of  claim 1 , wherein the transmitter and receiver are located on a single chipset and are in electrical communication with at least one antenna. 
     
     
       7. The method of  claim 1 , wherein the radio wave includes one of a low energy Bluetooth radio wave or a 2.4 GHz ISM band radio wave. 
     
     
       8. The method of  claim 1 , wherein the tire includes one of a Kevlar belted tire or a non-belted tire. 
     
     
       9. The method of  claim 1 , wherein the transmitter and receiver are aligned with an opening adjacent a metal belt in the tire. 
     
     
       10. The method of  claim 1 , wherein the radio wave is an ultra-wide band radio wave. 
     
     
       11. The method of  claim 10 , wherein the ultra-wide band radio wave is greater than or equal to 500 MHz's. 
     
     
       12. A device for measuring a tread depth of a tire comprising:
 a chipset; 
 at least one transmitter and at least one receiver located on the chipset; and 
 a microprocessor configured to perform the following operations: 
 transmitting at least one radio wave from the at least one transmitter through a tread of the tire; 
 receiving the at least one radio wave reflected from a road surface with the at least one receiver; and 
 determining the tread depth of the tire based on comparing the at least one radio wave reflected from the road surface with the at least one radio wave from the transmitter, 
 wherein determining the tread depth of the tire is based on at least one of measuring an elapsed time between when the at least one radio wave was transmitted by the transmitter and when the at least one radio wave reflected from the road surface was received by the receiver or measuring a phase of the at least one radio wave that was transmitted by the transmitter and a phase of the at least one radio wave reflected from the road surface and received by the receiver, 
 wherein the at least one radio wave includes a plurality of radio waves and the microprocessor generates a distance data set based the plurality of radio waves, and 
 wherein the smallest distance value of the distance data set corresponds to the tread depth of the tire.